Knowing how to measure for roller shades is the difference between a clean, fitted look and a shade that rubs the frame or leaves a gap of light. It takes about ten minutes per window, and you only need a steel tape measure and a pencil.
Most mistakes come from rushing or trusting that all windows in a room are the same. They usually are not. Here is a simple method for an inside mount, where the shade sits inside the window frame.
Before You Start
Use a steel tape, not a sewing tape. Fabric tape stretches and can throw you off by a few millimetres. Write every number down as you go, and label each window with a location, such as "kitchen left" or "bedroom centre."
Check that the window frame is deep enough. Roller shades need a small amount of depth to sit inside neatly. If your frame is too shallow, an outside mount, where the shade sits on the wall or trim, is the better option.
Step-by-Step: Measuring Width
Measure the width in three places: near the top, the middle, and the bottom of the window. Frames are rarely perfectly square, especially in older Toronto homes.
Use the smallest of the three numbers. That ensures the shade fits at the tightest point. Do not subtract anything yourself, because your installer or the manufacturer will account for the clearance they need.
Common Width Mistake
People often measure only the middle of the window. If the top is narrower, the shade will not go in. Always take all three.
Step-by-Step: Measuring Height
Do the same for height. Measure the left, centre, and right sides from the top of the inside frame to the sill. For height, the longest measurement is usually the safe one, since the shade can roll up inside the frame.
If you have a window crank or lock in the way, note it. These details affect the type of bracket and the final fit.
Common Height Mistake
Measuring to the bottom of the trim rather than the sill. The shade should end where the glass ends, unless you want it to hang lower for extra coverage.
Special Cases to Watch
Bay windows, angled corners, and condo windows with a sloped ledge need extra care. In those cases, it is smart to ask a professional to measure. A small error on a large window shows up quickly.
Motorized shades also need space for the motor and a power source. Plan ahead, and tell your consultant if you want the wiring hidden or prefer a battery or rechargeable option.
Why Professional Help Is Worth It
You can absolutely measure your own windows. But custom shades are an investment, and a wrong number can mean a remake. My Home Blinds offers exceptional customer service, and our team is happy to review your measurements or visit to measure for you.
Our high-end, quality products are made to the exact size, and our competitive pricing means you do not have to choose between quality and budget.
Frequently Asked Questions
Do I measure inside the frame or outside?
For an inside mount, measure inside the frame. For an outside mount, measure the area you want to cover, plus a few centimetres on each side.
Should I round my numbers?
Write down the exact measurement to the nearest millimetre or eighth of an inch. Let the maker handle any adjustments.
What if my windows are different sizes?
That is normal. Measure each window separately. Never assume two windows match.
Can I measure in winter?
Yes. Frames may shift slightly with temperature, but the effect is small. Measure carefully and you will be fine.
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